The present invention relates to a disk cartridge housing a disk such as an optical disk or a magneto-optical disk and a disk cartridge apparatus using such disks.
Optical disks and magneto-optical disks tend to lower an error rate upon reproduction or tend to cause a write error upon recording when their recording and reproducing surfaces are damaged or smudged. For this reason, it is customary that optical disks and magneto-optical disks are retained within rectangular cartridge cases so as not only to protect the disks, but also to prevent the disks from becoming difficult to handle.
Japanese Patent No. 2607054, for example, describes a disk cartridge. The disk cartridge and the disk cartridge apparatus using such disk cartridge according to the example of the prior art, as shown in FIG. 1, uses a rotatable lever 11 as an opening and closing mechanism for opening and closing a shutter 2. When the disk cartridge 1 is inserted into the disk cartridge apparatus, the lever 11 has a pin 13 which comes in contact with an end of a shutter 2 and the end of the shutter presses the lever as the disk cartridge is inserted into the disk cartridge apparatus, whereby the lever is rotated to slide the shutter, thereby resulting in an opening portion of the cartridge being exposed so as to allow the disk to be accessed. A coil spring 12 is attached to the lever so as to return the lever to the initial position when the disk cartridge is not inserted into the disk cartridge apparatus. Thus, the lever is biased in one direction under spring force. Since the coil spring biases the lever under spring force, when the disk cartridge is ejected from the disk cartridge apparatus, the lever is biased so as to return to the initial position under spring force as the disk cartridge is moved, thereby controlling the opening and closing of the shutter. The above-mentioned arrangement requires a spring for spring-biasing the lever which is used as the shutter opening and closing mechanism.
In order to use a spring, the disk cartridge apparatus requires a space sufficient to dispose the spring. More particularly, for a coil spring, the disk apparatus requires a space having a thickness wider than a coil winding diameter. Thus, a thin disk cartridge apparatus cannot be obtained.